The above map gives a general view of the ground on which took place successively: the battle of the frontier, the retreat of the Allies, the victorious stand, and the pursuit of the retreating enemy. The distance from Paris to Verdun is 140 miles as the crow flies; from Charleroi to the Marne is 97 miles. In consequence of the tearing up of that fateful "scrap of paper" which preceded the invasion of Belgium by Germany, in violation of the common rights of man, the Battle of the Frontier (also called the Battle of Charleroi) was fought in August 1914 on the line Mons--Charleroi--Dinant--Saint-Hubert--Longwy--Metz. [Illustration: MAUNOURY] On August 22, 1914, and the two succeeding days this Allied offensive failed at Charleroi, in consequence of which the French Commander-in-chief, General Joffre, broke off contact with the enemy and ordered a general retreat. It was impossible to do otherwise as the enemy forces were greatly superior in numbers. Moreover, they were well equipped with powerful artillery and machine-guns, whereas the Franco-British forces were short of both. Lastly, the German soldier had long been trained in trench warfare, whereas the Allies had yet to learn this art. To help in readjusting the balance between the opposing forces, Joffre fell back in the direction of the French reserves. The respite thus afforded was utilized to re-arrange the commands, and to train the reserves in the form of warfare adopted by the Germans. Meanwhile, the latter greatly extended their line of communications and more or less tired themselves. Then began that heroic retreat, without precedent in history, which attained a depth of 122 miles, and in the course of which the Allied soldiers, though already fatigued, marched as much as thirty miles a day facing about from time to time and counter-attacking fiercely, often with success. The Germans followed in pursuit, overrunning the country like a plague of locusts. Using their left wing as a pivot, their right undertook a vast turning movement taking in Valenciennes, Cambrai, Péronne, and Amiens. By August 27 Joffre had fixed up a plan according to which the offensive was to be taken again at the first favourable opportunity. In view of the execution of this plan an important mass of troops, under the orders of General Maunoury, was formed on the French left. General Maunoury's task was to outflank at a given moment the German right wing while, at the same time, a general attack, or at least unflinching resistance, was to be made along the rest of the front. This was the Allies' reply to the turning movement of the German general Von Kluck.